Staging persistent disease and choriocarcinoma

The stage of GTT means whether the tumour is just in the womb or has spread to other areas of the body. Staging is important because treatment is decided according to the stage. The tests and scans that your doctors carry out when diagnosing your GTT give them information about the stage.

The staging system used for GTT is called the FIGO staging system. This system looks at the stage of disease and scores risk factors to work out which treatment you need. It uses a numbering system for both the stage and risk factor score.

If your hCG levels go back to normal soon after removal of the molar pregnancy, your doctor won't need to give you a stage. In most women the hCG level virtually disappears within 4 to 6 weeks of removing a molar pregnancy. This is because once the molar tissue has gone it can’t produce hCG. So apart from follow up blood and urine tests to check whether the molar tissue has come back, you won’t need any further treatment.

But you will need further tests to help stage your disease, if

• Your hCG level stays the same on 4 measurements over a period of 3 weeks or longer
• Your hCG goes up on 2 measurements in a row, over a period of at least 2 weeks
• Your hCG level is 20,000 IU/L (international units per litre) or more, 4 weeks after surgery
• Your hCG level stays high for 6 months or longer, even if the level is coming down
• There is evidence of choriocarcinoma in the tissue sample taken during removal of a molar pregnancy

There are 4 main stages. Stage 1 is an early tumour and stage 4 the most advanced.

Stage 1

This is the earliest stage of GTT when the tumour is only in the womb (uterus).

Stage 2

This is when the tumour has spread outside the womb to genital areas nearby, such as the vagina or ovary.

Stage 3

The GTT has spread to the lungs and may or may not be in the local area around the womb.

Stage 4

The disease has spread (metastasised) to other parts of the body.

When you are diagnosed with GTT your doctors look at certain risk factors that help them decide about chemotherapy treatment and which drugs you will need. The scores for each risk factor are 0,1,2 and 4. These risk factors are

• Age - the younger you are the lower your score
• The type of pregnancy you had - a molar pregnancy is low risk, an abortion or miscarriage means a slightly higher risk, and full term pregnancy gives a higher score
• Time between the end of pregnancy and your diagnosis - less than 4 months is a low score and more than a year is a higher score
• The hCG level in the blood - the higher the level of hCG the greater the score
• The amount of tumour spread - the more areas of your body the tumour has spread to, the higher the score
• The parts of your body affected - if the tumour has spread to the lungs or vagina it is a low score. Spread to the spleen or kidneys is a slightly higher score, and spread to the brain or liver is higher again
• The size of the tumour - the larger the tumour, the greater the score
• Previous chemotherapy - if you have already had chemotherapy for your GTT but it has come back, this increases your score further

Your scores are added up to give a total. Doctors group women into two groups - high risk or low risk. Low risk means your risk factor score is 6 or less, and high risk means your score is 7 or more.

Most women needing treatment after a molar pregnancy will have a low risk score.